1. Combine chipotle and sauce, garlic, orange juice, lime juice, vinegar, oregano, cumin, salt and pepper in a blender or mini food processor; blend or process until the chipotle is chopped and the mixture is relatively smooth. Pour into a sealable plastic bag, add pork and seal, squeezing out any excess air from the bag. Turn to coat with the marinade. Refrigerate at least 1 hour and up to 8 hours.
2. Preheat grill to high or heat a large indoor grill pan over high heat. Remove the pork from the marinade (discard marinade). Grill the pork, turning occasionally, until an instant-read thermometer inserted diagonally into the center of the meat registers 145°F, 12 to 15 minutes. Transfer the pork to a cutting board and let rest for 5 minutes before slicing.